Field of the Invention
The present invention relates to a control device for a hybrid vehicle, and more particularly to a control device for a hybrid vehicle for switching a travel mode of the vehicle depending on states of an internal combustion engine.
Description of the Related Art
In recent years, a hybrid vehicle has been developed that includes both an internal combustion engine and an electric motor used as power sources. Such a hybrid vehicle performs a fail-safe process such as fuel cut for limiting operation of the internal combustion engine if a control system for the internal combustion engine detects an abnormal sensor output. For example, Japanese Patent Laid-Open No. 2012-117377 discloses a control device including a main accelerator sensor and a sub-accelerator sensor, wherein when an abnormality occurs in both the main accelerator sensor and the sub-accelerator sensor, the control device shifts to an operation mode for limiting an accelerator opening to limit a vehicle speed.
For the hybrid vehicle described in Japanese Patent Laid-Open No. 2012-117377, the vehicle is driven by power of the electric motor and the internal combustion engine, and also a power generator is driven by the power of the internal combustion engine to generate electric power, which is stored in a storage battery.
However, when an abnormality occurs in a sensor of a control system for the internal combustion engine in the hybrid vehicle as described in Japanese Patent Laid-Open No. 2012-117377, for example, performing a fail-safe process for stopping operation of the internal combustion engine is not preferable because the vehicle is caused to travel by the power from the electric motor and the internal combustion engine, and thus power for causing the vehicle to travel is insufficient, thereby making it difficult to properly retract the vehicle.